Figure 6.

EPR spectra of preloaded TEMPO in T. latifolia pollen. Prehydrated pollen was incubated for 5 min in germination medium that was replaced by a TEMPO/ferricyanide (1 mm:120 mm) solution. After 5 more min, the pollen was filtered and EPR spectra were recorded in the hydrated state in the presence of minute amounts of the solution (a) and after 5 h of exposure of the pollen to air (moisture content = 0.16 g water g⁻¹ DW) (b). The arrow in b points to the anisotropic spectrum, representing slow-moving TEMPONE molecules trapped in a solid environment.